eprintid: 22358
rev_number: 15
eprint_status: archive
userid: 2894
dir: disk0/00/02/23/58
datestamp: 2017-01-02 14:54:24
lastmod: 2017-01-19 09:43:13
status_changed: 2017-01-02 14:54:24
type: doctoralThesis
metadata_visibility: show
creators_name: Weyland, Marvin
title: Atomic excitation and molecular dissociation by low energy electron collisions
subjects: ddc-530
divisions: i-130001
divisions: i-851340
adv_faculty: af-13
abstract: In this work, momentum imaging experiments have been conducted for the electron impact excitation of metastable states in noble gases and for dissociative electron attachment (DEA) in polyatomic molecules. 
For the electron impact excitation study a new experimental technique has been developed which is able to measure the scattering angle distribution of the electrons by detection of the momentum transfer to the atoms. Momentum transfer images have been recorded for helium and neon at fixed electron impact energy close to the excitation threshold and good agreement with current R-matrix theory calculations was found.

A new momentum imaging apparatus for negative ions has been built for the purpose of studying DEA in biologically relevant molecules. During this work, DEA was investigated in the molecules ammonia, water, formic acid, furan, pyridine and in two chlorofluorocarbons. Furthermore, the change of DEA resonance energies when molecules form clusters compared to monomers was investigated in ammonia and formic acid. The experimental results of most studied molecules could be compared to recent theoretical calculations and they support further development in the theoretical description of DEA. The new apparatus built in this work also delivered a superior momentum resolution compared to existing setups. This allows the momentum imaging of heavier fragments and fragments with lower kinetic energy.
date: 2016
id_scheme: DOI
id_number: 10.11588/heidok.00022358
ppn_swb: 1655366432
own_urn: urn:nbn:de:bsz:16-heidok-223583
date_accepted: 2016-11-16
advisor: HASH(0x55d997a8ef90)
language: eng
bibsort: WEYLANDMARATOMICEXCI2016
full_text_status: public
citation:   Weyland, Marvin  (2016) Atomic excitation and molecular dissociation by low energy electron collisions.  [Dissertation]     
document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/22358/1/thesis_weyland_print.pdf